Extinct species of de genus Homo incwude Homo erectus, extant during roughwy 1.9 to 0.4 miwwion years ago, and a number of oder species (by some audors considered subspecies of eider H. sapiens or H. erectus).

The age of speciation of H. sapiens out of ancestraw H. erectus (or an intermediate species such as Homo antecessor) is estimated to have been roughwy 350,000 years ago.[2] Sustained archaic admixture is known to have taken pwace bof in Africa and (fowwowing de recent Out-Of-Africa expansion) in Eurasia, between about 100,000 and 30,000 years ago.

The species was initiawwy dought to have emerged from a predecessor widin de genus Homo around 300,000 to 200,000 years ago.[5]
A probwem wif de morphowogicaw cwassification of "anatomicawwy modern" was dat it wouwd not have incwuded certain extant popuwations.
For dis reason, a wineage-based (cwadistic) definition of H. sapiens has been suggested, in which H. sapiens wouwd by definition refer to de modern human wineage fowwowing de spwit from de Neanderdaw wineage. Such a cwadistic definition wouwd extend de age of H. sapiens to over 500,000 years.[6]

Extant human popuwations have historicawwy been divided into subspecies, but since around de 1980s aww extant groups have tended to be subsumed into a singwe species, H. sapiens, avoiding division into subspecies awtogeder.[7]

Some sources show Neanderdaws (H. neanderdawensis) as a subspecies (H. sapiens neanderdawensis).[8][9] Simiwarwy, de discovered specimens of de H. rhodesiensis species have been cwassified by some as a subspecies (H. sapiens rhodesiensis), awdough it remains more common to treat dese wast two as separate species widin de genus Homo rader dan as subspecies widin H. sapiens.[10]

The subspecies name H. sapiens sapiens is sometimes used informawwy instead of "modern humans" or "anatomicawwy modern humans". It has no formaw audority associated wif it.[11]
By de earwy 2000s, it had become common to use H. s. sapiens for de ancestraw popuwation of aww contemporary humans, and as such it is eqwivawent to de binomiaw H. sapiens in de more restrictive sense (considering H. neanderdawensis a separate species).[12]

Age and speciation process

Schematic representation of de emergence of H. sapiens from earwier species of Homo. The horizontaw axis represents geographic wocation; de verticaw axis represents time in miwwions of years ago (bwue areas denote de presence of a certain species of Homo at a given time and pwace; wate survivaw of robust austrawopidecines awongside Homo is indicated in purpwe). Based on Springer (2012), Homo heidewbergensis[13] is shown as diverging into Neanderdaws, Denisovans and H. sapiens. Wif de rapid expansion of H. sapiens after 60 kya, Neanderdaws, Denisovans and unspecified archaic African hominins are shown as again subsumed into de H. sapiens wineage.

Derivation from H. erectus

A modew of de phywogeny of H. sapiens during de Middwe Paweowidic. The horizontaw axis represents geographic wocation; de verticaw axis represents time in dousands of years ago.[2] Neanderdaws, Denisovans and unspecified archaic African hominins are shown as admixed into de H. sapiens wineage. In addition, prehistoric Archaic Human and Eurasian admixture events in modern African popuwations are indicated.

The speciation of H. sapiens out of archaic human varieties derived from H. erectus is estimated as having taken pwace over 350,000 years ago, as de Khoisan spwit from oder popuwations is dated between 260,000 and 350,000 years ago.[14]

An awternative suggestion defines H. sapienscwadisticawwy as incwuding de wineage of modern humans since de spwit from de wineage of Neanderdaws, roughwy 500,000 to 800,000 years ago.

The time of divergence between archaic H. sapiens and ancestors of Neanderdaws and Denisovans caused by a genetic bottweneck of de watter was dated at 744,000 years ago, combined wif repeated earwy admixture events and Denisovans diverging from Neanderdaws 300 generations after deir spwit from H. sapiens, as cawcuwated by Rogers et aw. (2017).[15]

Since de 2000s, de avaiwabiwity of data from archaeogenetics and popuwation genetics has wed to de emergence of a much more detaiwed picture, intermediate between de two competing scenarios outwined above: The recent Out-of-Africa expansion accounts for de predominant part of modern human ancestry, whiwe dere were awso significant admixture events wif regionaw archaic humans.[17]

Since de 1970s, de Omo remains, dated to some 195,000 years ago, have often been taken as de conventionaw cut-off point for de emergence of "anatomicawwy modern humans". Since de 2000s, de discovery of owder remains wif comparabwe characteristics, and de discovery of ongoing hybridization between "modern" and "archaic" popuwations after de time of de Omo remains, have opened up a renewed debate on de "age of H. sapiens", in journawistic pubwications cast[cwarification needed][uncwear; two main verbs in sentence] into terms of "H. sapiens may be owder dan previouswy dought".[18]H. s. idawtu, dated to 160,000 years ago, has been postuwated as an extinct subspecies of H. sapiens in 2003.[19]H. neanderdawensis, which became extinct about 40,000 years ago, has awso been cwassified as a subspecies, H. s. neanderdawensis.

H. heidewbergensis, dated 600,000 to 300,000 years ago, has wong been dought to be a wikewy candidate for de wast common ancestor of de Neanderdaw and modern human wineages.
However, genetic evidence from de Sima de wos Huesos fossiws pubwished in 2016 seems to suggest dat H. heidewbergensis in its entirety shouwd be incwuded in de Neanderdaw wineage, as "pre-Neanderdaw" or "earwy Neanderdaw", whiwe de divergence time between de Neanderdaw and modern wineages has been pushed back to before de emergence of H. heidewbergensis, to cwose to 800,000 years ago, de approximate time of disappearance of H. antecessor.[20][21]

Earwy Homo sapiens

Skhuw V (dated at about 80,000–120,000 years owd) exhibiting a mix of archaic and modern traits.

The term Middwe Paweowidic is intended to cover de time between de first emergence of H. sapiens (roughwy 300,000 years ago) and de emergence of fuww behavioraw modernity (roughwy 50,000 years ago).

Many of de earwy modern human finds, wike dose of Omo, Herto, Skhuw, Jebew Irhoud and Peștera cu Oase exhibit a mix of archaic and modern traits.[22][23][24]
Skhuw V, for exampwe, has prominent brow ridges and a projecting face. However, de brain case is qwite rounded and distinct from dat of de Neanderdaws and is simiwar to de brain case of modern humans. It is uncertain wheder de robust traits of some of de earwy modern humans wike Skhuw V refwects mixed ancestry or retention of owder traits.[25][26]

The "graciwe" or wightwy buiwt skeweton of anatomicawwy modern humans has been connected to a change in behavior, incwuding increased cooperation and "resource transport".[27]

There is evidence dat de characteristic human brain devewopment, especiawwy de prefrontaw cortex, was due to "an exceptionaw acceweration of metabowome evowution ... parawwewed by a drastic reduction in muscwe strengf. The observed rapid metabowic changes in brain and muscwe, togeder wif de uniqwe human cognitive skiwws and wow muscwe performance, might refwect parawwew mechanisms in human evowution, uh-hah-hah-hah."[28]
The Schöningen spears and deir correwation of finds are evidence dat compwex technowogicaw skiwws awready existed 300,000 years ago, and are de first obvious proof of an active (big game) hunt.
H. heidewbergensis awready had intewwectuaw and cognitive skiwws wike anticipatory pwanning, dinking and acting dat so far have onwy been attributed to modern man, uh-hah-hah-hah.[29][30]

The ongoing admixture events widin anatomicawwy modern human popuwations make it difficuwt to estimate de age of de matriwinear and patriwinear most recent common ancestors of modern popuwations (Mitochondriaw Eve and Y-chromosomaw Adam). Estimates of de age of Y-chromosomaw Adam have been pushed back significantwy wif de discovery of an ancient Y-chromosomaw wineage in 2013, to wikewy beyond 300,000 years ago.[31]
There have, however, been no reports of de survivaw of Y-chromosomaw or mitochondriaw DNA cwearwy deriving from archaic humans (which wouwd push back de age of de most recent patriwinear or matriwinear ancestor beyond 500,000 years).[32]

Fossiw teef found at Qesem Cave (Israew) and dated to between 400,000 and 200,000 years ago have been compared to de dentaw materiaw from de younger (120,000–80,000 years ago) Skhuw and Qafzeh hominins.[33]

Dispersaw and archaic admixture

Overview map of de peopwing of de worwd by anatomicawwy modern humans (numbers indicate dates in dousands of years ago [ka])

Dispersaw of earwy H. sapiens begins soon after its emergence, as evidenced by de Norf African Jebew Irhoud finds (dated to between 280,000 and 350,000 years ago).[24]
There is indirect evidence for modern human presence in West Asia around 270,000 years ago and Dawi Man from China is dated at 260,000 years ago.[34]

Among extant popuwations, de Khoi-San (or "Capoid") hunters-gaderers of Soudern Africa may represent de human popuwation wif de earwiest possibwe divergence widin de group homo Sapiens Sapiens. Their separation time has been estimated in a 2017 study to be as wong as between 260,000 and 350,000 years ago, compatibwe wif de estimated age of H. sapiens.[35]H. s. idawtu, found at site Middwe Awash in Ediopia, wived about 160,000 years ago.[36], and H. Sapiens wived at Omo Kibish in Ediopia about 195,000 years ago. [37]
Fossiw evidence for modern human presence in West Asia is ascertained for 177,000 years ago,
[38]
and disputed fossiw evidence suggests expansion as far as East Asia by 120,000 years ago.[39][40]

A significant dispersaw event, widin Africa and to West Asia, is associated wif de African "megadroughts" during MIS 5, beginning 130,000 years ago.[41]
A 2011 study wocated de origin of basaw popuwation of contemporary human popuwations at 130,000 years ago, wif de Khoi-San representing an "ancestraw popuwation cwuster" wocated in soudwestern Africa (near de coastaw border of Namibia and Angowa).[42]

Evidence for de overwhewming contribution of dis "recent" (L3-derived) expansion to aww non-African popuwations was estabwished based on mitochondriaw DNA, combined wif evidence based on physicaw andropowogy of archaic specimens, during de 1990s and 2000s.[44]
The assumption of compwete repwacement has been revised in de 2010s wif de discovery of admixture events (introgression) of popuwations of H. sapiens wif popuwations of archaic humans over de period of between roughwy 100,000 and 30,000 years ago, bof in Eurasia and in Sub-Saharan Africa. Neanderdaw admixture, in de range of 1-4%, is found in aww modern popuwations outside of Africa, incwuding in Europeans, Asians, Papuan New Guineans, Austrawian Aboriginaws, and Native Americans.[45][46] This suggests dat interbreeding between Neanderdaws and anatomicawwy modern humans took pwace after de recent "out of Africa" migration, wikewy between 60,000 and 40,000 years ago.[47] Recent admixture anawyses have added to de compwexity, finding dat Eastern Neanderdaws derive up to 2% of deir ancestry from anatomicawwy modern humans who weft Africa some 100 kya.[48]
The extent of Neanderdaw admixture (and introgression of genes acqwired by admixture) varies significantwy between contemporary raciaw groups, being absent in Africans, intermediate in Europeans and highest in East Asians. Certain genes rewated to UV-wight adaptation introgressed from Neanderdaws have been found to have been sewected for in East Asians specificawwy from 45,000 years ago untiw around 5,000 years ago.[49]
The extent of archaic admixture is of de order of about 1% to 4% in Europeans and East Asians, and highest among Mewanesians (Denisova hominin admixture), at 4% to 6%.[50]
Cumuwativewy, about 20% of de Neanderdaw genome is estimated to remain present spread in contemporary popuwations.[51]

Anatomy

Generawwy, modern humans are more wightwy buiwt (or more "graciwe") dan de more "robust" archaic humans.
Neverdewess, contemporary humans exhibit high variabiwity in many physiowogicaw traits, and may exhibit remarkabwe "robustness". There are stiww a number of physiowogicaw detaiws which can be taken as rewiabwy differentiating de physiowogy of Neanderdaws vs. anatomicawwy modern humans.

Anatomicaw modernity

The term "anatomicawwy modern humans" (AMH) is used wif varying scope depending on context, to distinguish "anatomicawwy modern" Homo sapiens from
archaic humans such as Neanderdaws and Middwe and Lower Paweowidic hominins wif transitionaw features intermediate between H. erectus, Neanderdaws and earwy AMH cawwed archaic Homo Sapiens.[52][53]
In a convention popuwar in de 1990s, Neanderdaws were cwassified as a subspecies of H. sapiens, as H. s. neanderdawensis, whiwe AMH (or European earwy modern humans, EEMH) was taken to refer to "Cro-Magnon" or H. s. sapiens.
Under dis nomencwature (Neanderdaws considered H. sapiens), de term "anatomicawwy modern Homo sapiens" (AMHS) has awso been used to refer to EEMH ("Cro-Magnons").[54]
It has since become more common to designate Neanderdaws as a separate species, H. neanderdawensis, so dat AMH in de European context refers to H. sapiens (but de qwestion is by no means resowved[55]).

In dis more narrow definition of H. sapiens, de subspecies H. s. idawtu, discovered in 2003, awso fawws under de umbrewwa of "anatomicawwy modern".[56]
The recognition of H. s. idawtu as a vawid subspecies of de anatomicawwy modern human wineage wouwd justify de description of contemporary humans wif de subspecies name H. s. sapiens.

A furder division of AMH into "earwy" or "robust" vs. "post-gwaciaw" or "graciwe" subtypes has since been used for convenience.
The emergence of "graciwe AMH" is taken to refwect a process towards a smawwer and more fine-boned skeweton beginning around 50,000–30,000 years ago.[57]

The cranium wacks a pronounced occipitaw bun in de neck, a buwge dat anchored considerabwe neck muscwes in Neanderdaws. Modern humans, even de earwier ones, generawwy have a warger fore-brain dan de archaic peopwe, so dat de brain sits above rader dan behind de eyes. This wiww usuawwy (dough not awways) give a higher forehead, and reduced brow ridge. Earwy modern peopwe and some wiving peopwe do however have qwite pronounced brow ridges, but dey differ from dose of archaic forms by having bof a supraorbitaw foramen or notch, forming a groove drough de ridge above each eye.[58] This spwits de ridge into a centraw part and two distaw parts. In current humans, often onwy de centraw section of de ridge is preserved (if it is preserved at aww). This contrasts wif archaic humans, where de brow ridge is pronounced and unbroken, uh-hah-hah-hah.[59]

Modern humans commonwy have a steep, even verticaw forehead whereas deir predecessors had foreheads dat swoped strongwy backwards.[60] According to Desmond Morris, de verticaw forehead in humans pways an important rowe in human communication drough eyebrow movements and forehead skin wrinkwing.[61]

Brain size in bof Neanderdaws and AMH is significantwy warger on average (but overwapping in range)
dan brain size in H. erectus. Neanderdaw and AMH brain sizes are in de same range, but dere are differences in de rewative sizes of individuaw brain areas, wif significantwy warger visuaw systems in Neanderdaws dan in AMH.[62][63]

Jaw anatomy

Compared to archaic peopwe, anatomicawwy modern humans have smawwer, differentwy shaped teef.[64][65]
This resuwts in a smawwer, more receded dentary, making de rest of de jaw-wine stand out, giving an often qwite prominent chin, uh-hah-hah-hah. The centraw part of de mandibwe forming de chin carries a trianguwarwy shaped area forming de apex of de chin cawwed de mentaw trigon, not found in archaic humans.[66] Particuwarwy in wiving popuwations, de use of fire and toows reqwire fewer jaw muscwes, giving swender, more graciwe jaws. Compared to archaic peopwe, modern humans have smawwer, wower faces.

Body skeweton structure

The body skewetons of even de earwiest and most robustwy buiwt modern humans were wess robust dan dose of Neanderdaws (and from what wittwe we know from Denisovans), having essentiawwy modern proportions. Particuwarwy regarding de wong bones of de wimbs, de distaw bones (de radius/uwna and tibia/fibuwa) are nearwy de same size or swightwy shorter dan de proximaw bones (de humerus and femur). In ancient peopwe, particuwarwy Neanderdaws, de distaw bones were shorter, usuawwy dought to be an adaptation to cowd cwimate.[67] The same adaptation can be found in some modern peopwe wiving in de powar regions.[68]

Physiowogicaw or phenotypicaw changes have been traced to Upper Paweowidic mutations, such as de East Asian variant of de EDAR gene, dated to c. 35,000 years ago.[74]

Recent divergence of Eurasian wineages was sped up significantwy during de Last Gwaciaw Maximum, de Mesowidic and de Neowidic, due to increased sewection pressures and due to founder effects
associated wif migration.[75]
Awwewes predictive of wight skin have been found in Neanderdaws,
[76] but de awwewes for wight skin in Europeans and East Asians, associated wif KITLG and ASIP, are (as of 2012[update]) dought to have not been acqwired by archaic admixture but recent mutations since de LGM.[77]
Phenotypes associated wif de "white" or "Caucasian" popuwations of Western Eurasian stock emerge during de LGM, from about 19,000 years ago.
Average craniaw capacity in modern human popuwations varies in de range of 1,200 to 1,450 cm3 (aduwt mawe averages). Larger craniaw vowume is associated wif cwimatic region, de wargest averages being found in popuwations of Siberia and de Arctic.[78]
Bof Neanderdaw and EEMH had somewhat warger craniaw vowumes on average dan modern Europeans, suggesting de rewaxation of sewection pressures for warger brain vowume after de end of de LGM.[79]

The term "behavioraw modernity" is somewhat disputed. It is most often used for de set of characteristics marking de Upper Paweowidic, but
some schowars use "behavioraw modernity" for de emergence of H. sapiens around 200,000 years ago,[85] whiwe oders use de term for de rapid devewopments occurring around 50,000 years ago.[86][87][88] It has been proposed dat de emergence of behavioraw modernity was a graduaw process.[89]

In January 2018 it was announced dat modern human finds at Miswiya cave, Israew, in 2002, had been dated to around 185,000 years ago, de earwiest evidence of deir out of Africa migration, uh-hah-hah-hah.[90][91][92][93]

The eqwivawent of de Eurasian Upper Paweowidic in African archaeowogy is known as de Later Stone Age, awso beginning roughwy 40,000 years ago.
Whiwe most cwear evidence for behavioraw modernity uncovered from de water 19f century was from Europe, such as de Venus figurines and oder artefacts from de Aurignacian, more recent archaeowogicaw research has shown dat aww essentiaw ewements of de kind of materiaw cuwture typicaw of contemporary San hunter-gaderers in Soudern Africa was awso present by weast 40,000 years ago, incwuding digging sticks of simiwar materiaws used today, ostrich egg sheww beads, bone arrow heads wif individuaw maker's marks etched and embedded wif red ochre, and poison appwicators.[96] There is awso a suggestion dat "pressure fwaking best expwains de morphowogy of widic artifacts recovered from de c. 75-ka Middwe Stone Age wevews at Bwombos Cave, Souf Africa. The techniqwe was used during de finaw shaping of Stiww Bay bifaciaw points made on heat‐treated siwcrete."[97]
Bof pressure fwaking and heat treatment of materiaws were previouswy dought to have occurred much water in prehistory, and bof indicate a behaviourawwy modern sophistication in de use of naturaw materiaws. Furder reports of research on cave sites awong de soudern African coast indicate dat "de debate as to when cuwturaw and cognitive characteristics typicaw of modern humans first appeared" may be coming to an end, as "advanced technowogies wif ewaborate chains of production" which "often demand high-fidewity transmission and dus wanguage" have been found at Pinnacwe Point Site 5–6. These have been dated to approximatewy 71,000 years ago. The researchers suggest dat deir research "shows dat microwidic technowogy originated earwy in Souf Africa, evowved over a vast time span (c. 11,000 years), and was typicawwy coupwed to compwex heat treatment dat persisted for nearwy 100,000 years. Advanced technowogies in Africa were earwy and enduring; a smaww sampwe of excavated sites in Africa is de best expwanation for any perceived 'fwickering' pattern, uh-hah-hah-hah."[98]
These resuwts suggest dat Late Stone Age foragers in Sub-Saharan Africa had devewoped modern cognition and behaviour by at weast 50,000 years ago.[99]
The change in behavior has been specuwated to have been a conseqwence of an earwier cwimatic change to much drier and cowder conditions between 135,000 and 75,000 years ago.[100]
This might have wed to human groups who were seeking refuge from de inwand droughts, expanded awong de coastaw marshes rich in shewwfish and oder resources. Since sea wevews were wow due to so much water tied up in gwaciers, such marshwands wouwd have occurred aww awong de soudern coasts of Eurasia. The use of rafts and boats may weww have faciwitated expworation of offshore iswands and travew awong de coast, and eventuawwy permitted expansion to New Guinea and den to Austrawia.[101]

^This is a matter of convention (rader dan a factuaw dispute), and dere is no universaw consensus on terminowogy.
Some schowars incwude humans of up to 600,000 years ago under de same species. See Handbook of Deaf and Dying, Vowume 1. Cwifton D. Bryant. 2003. p. 811.
See awso: Masters of de Pwanet: The Search for Our Human Origins. Ian Tattersaww. Page 82 (cf. Unfortunatewy dis consensus in principwe hardwy cwarifies matters much in practice. For dere is no agreement on what de 'qwawities of a man' actuawwy are," [...]).

^It is first used in de 1940s as a synonym of Linnaeus' H. s. europaeus, i.e. Caucasoids. Journaw of Mammawogy 26-27 (1944), p. 359.
This usage is abandoned by de 1970s, and H. s. sapiens was now used for Cro-Magnon
by audors who wished to cwassify Neanderdaws as subspecies of H. sapiens taken in a wider sense, for exampwe, The Journaw of de American Scientific Affiwiation 22-25 (1970), p. 134.

^It is important to note dat dis is a qwestion of conventionaw terminowogy, not one of a factuaw disagreement. Pääbo (2014) frames dis as a debate dat is unresowvabwe in principwe, "since dere is no definition of species perfectwy describing de case."Pääbo, Svante (2014). Neanderdaw Man: In Search of Lost Genomes. New York: Basic Books. p. 237.